<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>es13的特性</title>
</head>
<body>
  <script>

    var str = "123"
    console.log(str.at(-1))

    var obj = {
      name: "123"
    }

    console.log(Object.hasOwn(obj, "name"))

    //对象属性
  </script>
</body>
</html>